167 lines
4.5 KiB
Groff
167 lines
4.5 KiB
Groff
.\" -*- nroff -*-
|
|
.\"
|
|
.\" Copyright (c) 1996 Doug Rabson
|
|
.\"
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This program is free software.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
|
|
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd July 24, 1996
|
|
.Os
|
|
.Dt VOP_ATTRIB 9
|
|
.Sh NAME
|
|
.Nm VOP_GETATTR ,
|
|
.Nm VOP_SETATTR
|
|
.Nd get and set attributes on a file or directory
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In sys/vnode.h
|
|
.Ft int
|
|
.Fn VOP_GETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" "struct thread *td"
|
|
.Ft int
|
|
.Fn VOP_SETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" "struct thread *td"
|
|
.Sh DESCRIPTION
|
|
These entry points manipulate various attributes of a file or directory,
|
|
including file permissions, owner, group, size,
|
|
access time and modification time.
|
|
.Pp
|
|
The arguments are:
|
|
.Bl -tag -width cred
|
|
.It Fa vp
|
|
The vnode of the file.
|
|
.It Fa vap
|
|
The attributes of the file.
|
|
.It Fa cred
|
|
The user credentials of the calling process.
|
|
.It Fa td
|
|
The thread.
|
|
.El
|
|
.Pp
|
|
Attributes which are not being modified by
|
|
.Fn VOP_SETATTR
|
|
should be set to the value
|
|
.Dv VNOVAL ;
|
|
.Fn VATTR_NULL
|
|
may be used to clear all the values, and should generally be used to reset
|
|
the contents of
|
|
.Fa *vap
|
|
prior to setting specific values.
|
|
.Sh LOCKS
|
|
.Fn VOP_GETATTR
|
|
expects the vnode to be locked on entry and will leave the vnode locked on
|
|
return.
|
|
The lock type can be either shared or exclusive.
|
|
.Pp
|
|
.Fn VOP_SETATTR
|
|
expects the vnode to be locked on entry and will leave the vnode locked on
|
|
return.
|
|
The lock type must be exclusive.
|
|
.Sh RETURN VALUES
|
|
.Fn VOP_GETATTR
|
|
returns 0 if it was able to retrieve the attribute data via
|
|
.Fa *vap ,
|
|
otherwise an appropriate error is returned.
|
|
.Fn VOP_SETATTR
|
|
returns zero if the attributes were changed successfully, otherwise an
|
|
appropriate error is returned.
|
|
.Sh PSEUDOCODE
|
|
.Bd -literal
|
|
int
|
|
vop_getattr(struct vnode *vp, struct vattr *vap,
|
|
struct ucred *cred, struct thread *td)
|
|
{
|
|
/*
|
|
* Fill in the contents of *vap with information from
|
|
* the file system.
|
|
*/
|
|
...;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
vop_setattr(struct vnode *vp, struct vattr *vap,
|
|
struct ucred *cred, struct thread *td)
|
|
{
|
|
/*
|
|
* Check for unsettable attributes.
|
|
*/
|
|
if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
|
|
(vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
|
|
(vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
|
|
((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (vap->va_flags != VNOVAL) {
|
|
/*
|
|
* Set the immutable and append flags of the file.
|
|
*/
|
|
}
|
|
|
|
if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
|
|
/*
|
|
* Change owner and/or group of the file.
|
|
*/
|
|
}
|
|
|
|
if (vap->va_size != VNOVAL) {
|
|
/*
|
|
* Truncate the file to the specified size.
|
|
*/
|
|
}
|
|
|
|
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
|
|
/*
|
|
* Change access and/or modification time of file.
|
|
*/
|
|
}
|
|
|
|
if (vap->va_mode != (mode_t)VNOVAL) {
|
|
/*
|
|
* Change permissions of file.
|
|
*/
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
.Ed
|
|
.Sh ERRORS
|
|
.Bl -tag -width Er
|
|
.It Bq Er EPERM
|
|
The file is immutable.
|
|
.It Bq Er EACCES
|
|
The caller does not have permission to modify the file or directory attributes.
|
|
.It Bq Er EROFS
|
|
The file system is read-only.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr VFS 9 ,
|
|
.Xr vnode 9 ,
|
|
.Xr VOP_ACCESS 9
|
|
.Sh AUTHORS
|
|
This manual page was written by
|
|
.An Doug Rabson .
|